bug#43004: 28.0.50; Test failures due to symlinked Emacs sources

[Dmitry Gutov <dgutov@yandex.ru>]

On 16.10.2020 23:54, Stephen Berman wrote:
> I've attached the output of two batch runs using the patched
> elisp-mode-tests.el.  The first run was executed from my home directory,
> the second run was executed from the partition the file is really
> located on, which is symlinked from my home directory:
> 
> (expand-file-name
> "~/src/emacs/emacs-master/test/lisp/progmodes/elisp-mode-tests.el")
> =>
> "/home/steve/src/emacs/emacs-master/test/lisp/progmodes/elisp-mode-tests.el"
> 
> (file-truename
> "/home/steve/src/emacs/emacs-master/test/lisp/progmodes/elisp-mode-tests.el")
> =>
> "/datadisk/steve/src/emacs/emacs-master/test/lisp/progmodes/elisp-mode-tests.el"
> 
> On the first run there are no unexpected failures, on the second, there
> are five unexpected failures.

So, what happens if you just remove the 'file-truename' call from the 
declaration of emacs-test-dir?

It was added by Glenn in c4ecc01a45, and there must be a reason for it, 
but it seems like it causes the current failures.

Ultimately, if we don't manage to fix it in an easy way, we could 
replace the

   (should (equal xref expected-xref))

comparison inside xref-elisp-test-run with multiple deeper comparisons 
(and use file-equal-p instead of equal for file names). Or call 
xref-location-marker and compare markers.